Designation
| Name |
The value |
| Designation GOST Cyrillic |
20ХНР |
| Designation GOST Latin |
20XHP |
| Transliteration |
20HNR |
| By chemical elements |
20CrНB |
Description
20KHNR steel is used: for the manufacture of gears, shaft gears, worms, dog clutch, rollers, fingers, bushings and other major loaded parts operating under conditions of shock loads.
Note
Structural steel high-quality chrome-Nickel with boron.
Standards
| Name |
Code |
Standards |
| Sheets and strips |
В23 |
GOST 103-2006 |
| Bars and shapes |
В22 |
GOST 1133-71, GOST 8319.0-75, GOST 2590-2006, GOST 2591-2006, GOST 2879-2006 |
| Bars and shapes |
В32 |
GOST 4543-71, GOST 7417-75, GOST 8559-75, GOST 8560-78, GOST 14955-77, TU 14-1-2118-77, TU 14-11-245-88, TU 14-136-367-2008 |
| Blanks. Of the workpiece. Slabs |
В31 |
OST 3-1686-90, TU 14-1-4944-90 |
Chemical composition
| Standard |
C |
S |
P |
Mn |
Cr |
Si |
Ni |
Fe |
Cu |
V |
B |
Ti |
| GOST 4543-71 |
0.16-0.23 |
≤0.035 |
≤0.035 |
0.6-0.9 |
0.7-1.1 |
0.17-0.37 |
0.8-1.1 |
Rest |
≤0.3 |
≤0.05 |
0.001-0.005 |
≤0.06 |
Fe is the basis.
According to GOST 4543-71 the content in high-quality steel is regulated: P≤0,025%; S≤0.025%; Сu≤0.30%; in high-grade steel: P≤0,025%; S≤0.015%; Сu≤0.25%.
Mechanical properties
| Section, mm |
t отпуска, °C |
sT|s0,2, MPa |
σU, MPa |
d5, % |
y, % |
KCU, kJ/m2 |
HB, MPa |
HRC |
| Normalizing at 930 °C, air cooling + tempering in oil from 840 °C to + vacation at 200 °C, air cooling |
| 15-25 |
- |
1370 |
1420 |
14 |
60 |
1060 |
- |
- |
| Normalizing at 930 °C, air cooling + tempering in oil from 840 °C to + vacation at 200 °C, air cooling |
| ≤25 |
- |
1370 |
1420 |
14 |
60 |
1060 |
418 |
- |
| Quenching in oil from 860 °C to + vacation, hladanie in oil |
| - |
200 |
1220 |
1520 |
10 |
54 |
481 |
- |
47 |
| Normalizing at 930 °C, air cooling + tempering in oil from 840 °C to + vacation at 200 °C, air cooling |
| 25-75 |
- |
970 |
1060 |
15 |
60 |
1060 |
- |
- |
| Normalizing at 930 °C, air cooling + tempering in oil from 840 °C to + vacation at 200 °C, air cooling |
| 100-150 |
- |
830 |
1000 |
16 |
- |
961 |
286 |
- |
| Quenching in oil from 860 °C to + vacation, hladanie in oil |
| - |
300 |
1200 |
1400 |
- |
- |
481 |
- |
46 |
| Normalizing at 930-950 °C, air cooling + tempering in oil with 780-830 °C + vacation at 200 °C, cooling in air or in oil |
| ≤15 |
- |
980 |
1180 |
10 |
50 |
863 |
- |
- |
| Normalizing at 930 °C, air cooling + tempering in oil from 840 °C to + vacation at 200 °C, air cooling |
| 25-50 |
- |
1110 |
1200 |
- |
62 |
1442 |
340 |
- |
| Quenching in oil from 860 °C to + vacation, hladanie in oil |
| - |
400 |
1180 |
1250 |
11 |
57 |
677 |
- |
43 |
| Normalizing at 930 °C, air cooling + tempering in oil from 840 °C to + vacation at 200 °C, air cooling |
| 50-75 |
- |
970 |
1060 |
15 |
60 |
1060 |
302 |
- |
| 75-100 |
- |
920 |
1000 |
15 |
60 |
1245 |
302 |
- |
| Quenching in oil from 860 °C to + vacation, hladanie in oil |
| - |
600 |
740 |
780 |
16 |
65 |
1687 |
- |
28 |
Description mechanical marks
| Name |
Description |
| sT|s0,2 |
Yield strength or limit of proportionality with a tolerance for residual deformation of 0.2% |
| σU |
Limit short-term strength |
| d5 |
Elongation after rupture |
| y |
The relative narrowing |
| KCU |
Toughness |
| HB |
Brinell hardness number |
| HRC |
Rockwell hardness (indenter diamond spheroconical) |
Technological properties
| Name |
The value |
| Weldability |
RDS. Recommended heating and subsequent heat treatment. |
| Склонность к отпускной хрупкости |
inclined |
| The temperature of forging |
Start - 1150 °C, the end - of 800 °C. |
| Flock-sensitive sensitivity |
sensitive |
